Protective helmets and headwear are known to protect a wearer's head from accidental trauma. For example, construction workers are often required to wear hard hats or other safety headwear due to the increased risk of falling objects in and around construction sites. Similarly, athletes are required to wear protective helmets, such as football, baseball, hockey, lacrosse, skiing, snowboarding, skydiving, and cycling helmets, to protect their heads in case of high impact collisions. These helmets are typically made of a hard and durable material designed to deflect and disperse the effects of external forces imparted thereto.
Various components of protective helmets and headwear are generally known in the art and have been described in previous patent references. For example, U.S. Pat. No. 6,763,524 discloses a helmet with a faceguard, U.S. Pat. No. 6,711,751 discloses a helmet with a polycarbonate shell and foam liner, and U.S. Publication No. US 2002/0120978 discloses a helmet with a slow recovery, viscoelastic, polymeric foam liner.
In addition to the important protective characteristics of such helmets, the helmets also need to be comfortable when worn because the helmet is typically worn for extended periods of time. To accommodate people with different head sizes, protective helmets are typically manufactured in various standard sizes, such as, small, medium, large, and extra large. To further enhance the comfort, fit, and shock absorption of a helmet, some helmets also include an internal support within the interior of the helmet. The internal support is often adjustable to provide a custom fit on the wearer's head.
Recent advancements in sports medicine have uncovered a particularly dangerous risk to athletes where indirect contact is imparted to the athlete's head, causing rotational or shear forces to the athlete's head. These forces have been found to result in severe cranial injuries, particularly concussions. Traditional helmets are designed to prevent injury from extreme direct forces imparted to the head, such as a direct collision with another athlete at high speed. However, traditional helmets do not provide adequate protection against rotational or shear force, from glancing blows for example, that need not be nearly as powerful to cause a concussion or other severe injury as direct impact collisions.
Thus, there remains a need for a protective helmet that can provide cranial protection against rotational or shear forces, while still protecting against direct impact forces.